Let me tell you some preludes:
The reason behind using 8 cores was to put in a pair of four aggressively powerful quad processors
like the cortex A15 with another pair of less powerful yet more power efficient four quad processors
like cortex A7.
This is the main intention
behind putting all these 8 cores of ARM's big.little architecture. The purpose is to let the A15s handle power hungry tasks like web page opening, playing an asphalt 8 game etc while the a7s would handle "simple" tasks. This is more vividly demoed in this video:
Now, the way you are saying it is not a true 8 core processor as if you are
1. demanding 8 cortex A15 processors using 28 nm technology.
Do you know/have any idea what could happen if they all be available online at the same time in this case?
2. you knew there was a "true" octa core processor in the world, to be (or already) implemented in another device. IF SO, point us to that device and also explain what is the ideal to call a processor true 8 core.
It was never an intention of ARM to put eight A15s (for example) available for heterogeneous multi-processing.
. Again 64 bit A57s are to be paired with 32 bit A52s.
Even the S4 equipped with exynos 5410 is an octa core processor device. It is just that the bloody CCI (cache coherence interconnector, CCI400) was crippled to enable all the 8 cores available online. Once the 8 cores packed in a SoC like this it is an octa core processor device. Whether or not you like it to call true 8 core.
Samsung/ARM worked on this and released another SoC (in the form of upgraded exynos) which has a working CCI that is free from the above mentioned flaw(s) which will have Cluster Migration by default
and will receive the update that is made from Linaro team to enable all the 8 cores available online and therefore will become
a "TRULY WORKING" 8 core processor which is implemented in Note 3.
These are facts, these have been heavily discussed in the general section of Samsung Galaxy S4 forums.
Oh, another thing- just because all these 8 cores are made to be available online
it does not mean all the 8 cores will be working Simultaneously regardless of what application is in the process. Depending on the needs of the app(s) all these 8 cores (ranging from 1 core to the extreme case- 8 cores) can be used. If an app needs 4 cores, they can be used. If it needs 6 cores then they can be used. If it needs 8 cores then they can be used.
I personally am curious to see how it be going when all the 8 cores were used for an app.
And to the OP who's demadning a straight answer, my thoughts:
we do not know anything atm how power efficient and cool it'd be to have the HMP doing all these tasks. This requires
real life buyers buy the device
start playing with it
see how hot the device becomes (compared to another exynos device like s4).
It actually depends on those stuffs. You demand the answer as if we all knew from the beginning how exynos 5420 gonna perform in real life.